Asymmetric synthesis based on enolate chemistry:: β-lactam synthesis and memory of chirality

Two topics are described concerning asymmetric synthesis based on enolate chemistry. The first one is stereoselective beta -lactam synthesis through oxidative coupling of dienolates generated from acyclic tertiary amides. The stereochemistry of beta -laclam formation depends on the oxidant used. The second one is asymmetric alpha -alkylation of chiral ketones and alpha -amino acid derivatives, in which chirality of starting materials is preserved (memorized) in enolate intermediates as dynamic chirality. Thus, optically active alpha -alkylated products are obtained directly without using any external chiral sources.(1)).